Process for vulcanizing rubber and products obtained thereby



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SIDNEY Ill. 1UAlllllt 'lilliL, 01F LEONIA, NEW .rnnsnv, :ASSTGNUR TUTHEATAJUGATUGK GHEMIICAL COMPANY}, CURTURATTUN Ull CUNMECTICUT.

rnocnss ron vuncanr[z ne nennnn nun rnonecrs onrarnnn rnnnnnr.

No Drawing. l Division or joint application of Etidney M. Gadwcll andClaude D. Jltason,

filed a i-u re,

ieao, serial in. smart. niviuea and this application filed November re,mac. eel-mi nu. aerate.

To allwhmh. it may concern:

' Be it, known that l, SIDNEY M. Canwnnt, a citizen of the llnitedStates, residing at Leonia, county of Bergen, State of New Jersey, haveinvented certain new and useful Improvements in- Processes forVulcanizing Rubber and Products Obtained Thereby; of

which the following is a lull, clear, and exact description. v

This case is adivision of Serial No. 37A,- 275,,application of Cadwelland Mason, filed April16,1920.

This invention relates to processes for vulcanizing rubber .-andproducts obtained thereby. lit is more particularly directed to theprocess for vulcanizing rubber in the presence of an organic acceleratorand products obtained thereby.

, Ttis known that the time and temperature involved-in the vulcanizationof. rubber as heretofore practiced may be regulated by the use ofaccelerators.- The class of accelerators which has been employed in themore recent processes has included theorganic accelerators and of theseorganic accelera-, tors the amies and their derivatives have providedperhaps the most promising group.

Of these amine derivatives the carbon disulphide derivatives haveconstituted the faster dill accelerators; Among these tasteraccelerators aliphatic amine carbon disulphide derivatives have appearedmost promising. One disadvantage of such aliphatic amine acceleratorshas been that the raw materials from which they are produced areexpensive andmust be used inua relatively high state of purity inorderto avoid the occurrence in the finished accelerator of objectionable byproducts. v

The object of the present invention accordingly is to provide aneflicient process comprising an eccelerator which may he made fromrelatively inexpensive raw materials and materials which in manyinstances may be employed in a relatively impure conditlon without theresence t obyectionahle lay-products. Anot erobject of the invention isto provide asimple processol vulcani-- nation comprising an ecceleratorin sulhcient quantity and for a length of time to prov de, an optimumvulcanization. Another ob ect (it the invention is to provide a processof the hind described employing an accelerator tree from odor, andpoisonous characteristics. Another object of the invention is to providea i series ofproducts having i'm:

proved physical characteristics in general,

and also the product from a process such as that outlined above.

The inventionaccordingly consists of a material which comprisescombining theg 'stituted alkyl and 'aryl'groups and vulcanizing-therubber. llncarrying out the inven;

tion in its ber, 10 parts of zinc oxide. 3 parts of sul phur and partdimethyldiphenylthiuramdisulphide are mixed on the mill at the ordinarytemperature and. for the usual time,

when mining is accomplished, and the material'is' vulcanized for 10minutes or longer under 40 lbs. steam pressure. The preferred method ofpreparation of this accelerator namely,dimethyldi-phenylthiuramdisulphide, is as follows: 48(1) partsmonomethylaniline, 170 parts carbon disulphide and 285 parts iodinedissolved'in alcohol are mixed and allowed to stand. The product whichis formed crystallizes outafter about two hours standing -and isfiltered, washed. with a little alcohol, and air dried. It is believedthat this compound has the following formula 2 no s-s-e-n can t v areDiphenyldimethylthiuramdisulphide a representative of a class of similarcompounds which may be employed in accelepret'erred form parts of rulerating vulcanization, and among these sub:

stances may be mentioned the following:

Diethyldip'henylthiui'amdisulphide n+o-s s o-1v j r'lDiparamethylphenylenedimethylthiuram 'disulfide v v f rem-an enicnip,

nc -s s c n ou one It will be noted that employing va'ri s members otthegroup as given above ti. .t

vulcanization may be accomplished in a mold or in open heat or in anyother dessired manner.

The vulcanized rubber obtained as a re sult of the process herein setforth is substantially odorless and colorless. It possesses excellentphysical characteristics such as good tensile strength, resistance toflexing andabrasion, and excellently withstands the usual ageing tests.The quantity of sulphur employed for securing optimum vulcanization maybe so small when used with accelerators of the type herein describedthat blooming is substantially avoided.

It will thus be seen that among others the objects heretofore noted havebeen achieved.

As many apparently widely difl'erent embodiments of this invention maybe made without departing from the spirit thereof, it will be understoodthat we do not intend to limit ourselvesto the specific embodimentherein set forth except as indicated in the ap ended claims.

aving thus described my invention, what SIDNEY M. GADVELL.

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